Rodless pump



June 25, 1935. G. s. KNox RODLESS PUMP med may 29. 1954 5 Sheets-Sheet lI n d n n n n r l r r l f I I I l n n n n l n n v n r v v v u n n n n fAnrrnnnrnrA vnr vrlr inrlkc G. s.. KNox 2,005,995

RoDLEss Y PUMP Filed May 29, 1934 5 Sheets-Sheet 2 Jule 25, 193s.

5 Sheets-Sheet 5 III 'June 25, 1935. G. s. KNOX RODLESS PUMP Filed May29, 1954 5 Sheets-Sheet 4 Attorncy Patented June 25, 1935 l PATENTori-Ica RoDLEss PUMP Granville S. Knox, Los Angeles, Calif., assigner`to W. L. Cummings, Los Angeles, Calif.

Application May 29, 1934, Serial No. 728,078

15 Claims.V (Cl. 10S-46) This invention relates to self-contained orrodless pumps for oil wells, in which the pump unit itself contains ahydraulic motor for reciprocating the pump plunger, the motor beingactuated by oil at high pressure delivered from a source at the surfaceto the motor through small central tubing extending down through thewell within the oil tubing through which pumped oil is discharged fromthe pump up to the surface. In view of the obvious advantagesl of pumpsof the general type to which this invention relates over conventionalsucker rod pumps, many attempts have been made to develop commerciallysuccessful rodless pumps. However, serious obstacles have beenencountered during this development. `One defect of pumps which havebeen otherwise satisfactory is that their over all diameter has been toogreat to permit their entry into oil tubing of the small dimensionsnecessary 20 in many deep wells, thereby necessitating the mounting ofthe pump on the lower end of the oil tubing. 'Ihe disadvantage of thisarrangement is that both the inner and outer tubing strings have to bepulled whenever the pump is removed. `On the' other hand, a pump smallenough to enter into the outer tubing string can be removed by pullingonly the inner tubing without disturbing the outer tubing.

It has been impracticable to reduce the overall diameter of rodlesspumps, as they have been previously designed, below denite limitsbecause, to the best of my knowledge, such pumps comprised tubular bodymembers containing pump and/or motor barrels with several fluid passagesthe over allv diameter of the body member were reduced in size, it wasnecessary to reduce the size of the barrel or of the iluid passages tosuch an extent as to greatly reduce the capacity of the pump.

An important object of the present invention is to reduce the over alldiameter of a rodless pump suilicient to permit its insertion in oiltubing of reasonable size without unduly decreasing its eiiiciency ofoperation. This object is attained by employing in the motor a travelingbarrel and stationary piston construction instead of the usualstationary barrel and traveling piston, and positioning the valvemechanism which controls the flow of fluid to and from the workingchamber of the motor within the stationary piston assembly. This permitsthe use of short iluid passages extending through the piston assemblyinstead oi longitudinally outside of the barrel, for

extending past one'at least of the barrelsand, ifV

drawings.

carrying fluid to and from the working chamber.

Another object of the invention is to provide a rodless pump assembly inwhich the pump is readily removable as a unit from the motor with- 5 outdisassembling the motor. This permits the use of the same motor operatedby fluid at the same pressure in Wells of different depths by merelysubstituting pumping units of diilerent capacities. It also permitsready replacement of 10 a worn pumping unit.

` Another object is to provide a rodless pumping unit in which the motoris fully enclosed and all its moving parts protected from contact withpumped oil fromthe well, which pumped oil often contains vsand and gritdestructive to a moving mechanism.

Another` object is to provide a pump structure adapted to be attached totheI lower end of the inner tubing and lowered into and removable fromthe well on the inner tubing but in which the weight of the inner tubingis supported from the outer tubing independent of the pump when thelatter is in working position, thereby preventing possible distortion ofthe pump by the weight of the inner tubing.

Another object is to provide a. oating working barrel in the motorsupported only at one end so that it automatically aligns itself withthe plunger and is also relieved of allunnecessary compression ortension strains which might tend to warp the barrel and freeze theenclosed plunger.

Another object is to provide a. rodless pump motor having ahydraulically actuated workingvalve, which valve is light in weight, hasa short stroke and is cushioned at the end of each stroke to eliminateshock and thereby insure long life and high eiliciency.

Another object is to provide a simple and positive locking mechanism forholding the valve mechanism in a desired position while the pump isbeing transported to and lowered into a well, whereby any necessity forpriming the motor at the surface before lowering it into the well iseliminated. Heretofore with pumps of this type such priming hasbeennecessary to uuid-lock the valve mechanism in an operative position.

Other objects and various specic features of the invention will becomeapparent from the fol- 50 lowing detailed description which refers tothe In the drawings: Figs. 1 to 4 are schematic diagram illustrating theprinciple ci operation oi my pump, the four 56 Fig. 10A is alongitudinal sectional view show- Ing a modification of that portion ofthe pump structure disclosed in Fig.- 10;

Fig. 13 is a cross section of the pump taken in t the piane :nnxm ofFig. 6;

Fig. 14 is a cross section taken in the: plane XIV-XIV of Fig. 7;

Fig. 15 is a cross section taken in the plane XV-XV of Fig. 9; 1

Fig. 16 is a cross`section taken in the plane XVI- XVI of Fig. 10;

Fig. 17 is a cross section taken in the vplane XVII- XVII of Fig. 10;

Fig. 18 is a cross section taken in the .plane XVIII- XVIII of Fig. 12,and

Fig. 19 is a detail vertical section illustrating a preferred method ofjoining adjacent sections of my pump.

Principles of operation A complete understanding of the construction andoperation of my pump can be most quickly conveyed by first explainingthe general principles of operationI with reference to the schematicdiagrams of Figs. 1, 2, 3, and 4 and then following through the detailsof construction of an actual pump as disclosed in Figs. to 18,inclusive.

Referring to Fig. 1, there is shown a well casing I, within which arepositioned an outer tubing string 2 and an inner tubing string 3, thesestrings extending from that portion of the casing in which the pump islocated upwardly through the casing to the surface. The outer tubing 2constitutes the usual oil tubing through which pumped oil is deliveredto the surface. The inner tubing 3 constitutes a conduit for thetransmission of clean oil at high pressure from the surface down to thepump unit for operating the latter. It is to be understood that theouter tubing 2 may be extended clear to the bottom of the well and besupported, in part atleast, by an anchor placed on the lower endthereof. Ordinarily, of course, the pumping unit is positioned closelyadjacent the bottom of the well and submerged in the oil which stands inthe casing I.

The pumping unit when positioned in the well is supported from the outertubing 2 and to this end the tubing is provided with an inwardlyprojecting shoulder II, the inner edge of which is beveled to constitutea seat for supporting and sealing with a block I2 on a stationary motorplunger and pump barrel assembly d. Block I2 and shoulder Il togetherconstitute a partition in the outer tubing 2 so that exhaust oil fromthe motor and pumped oil from the pump delivered into the outer tubing 2above the shoulder will be discharged to the surface of the well,whereas that portion of the tubing 2 below the shoulder will bepiled-with oil from the well, this oil being permitted to enter throughapertures I3. The component parts'of the stationary .motor plunger andpump barrel assembly 4' include a pump barrel I4 extending downwardlybelow the block I3, a connecting stem I5 extending upwardly from theblock I2 tothe plunger proper I6 having a lower shoulder Il and an uppershoulder I8., which plunger is connected at its upper end to the lowerend of 'the inner tubing 3.

The traveling motor barrel and pump plunger assembly 5 comprises abarrel I 9 which seals with the shoulders and I8, and together withthose shoulders and the portion of the motor plunger therebetween,defines the working chamber of the motor. The barrel I9 is provided withan inwardly extending shoulder 20 positioned intermediate the shouldersI1 and I8 on the plunger and which seals with the plunger andconstitutes the moving piston of the motor. The barrel I9 is secured atits lower end to a pump plunger rod 2| which extends through and sealswith the block I2 and terminates in a pump plunger 22. The plunger rod2| is hollow, as shown, and is provided with a ball check valve 23 atthe lower end. The upper end of the passage within the plunger rod 2|communicates through ports 24 with the interior of the outer tubing 2above the shoulder II. 'Ihe pump barrel Il is provided with a standingvalve 25 in the lower end thereof and with surge ports 26 in its upperend, these ports communicating with the space below the shoulder I I inthe outer tubing.

That portion of the stationary motor plunger assembly positioned withinthe working chamber of the motor is hollow, constituting a valve chest6, within which there is mounted a vertically reciprocable piston valve1, the latter being provided with four vertically spaced shoulders,which seal with the walls of the valve chest and define with the wallsof the valve chest three chambers or pockets 21, 28 and 29,respectively. The piston valve 'I is actuated by fluid pressuredelivered successively to opposite ends thereof and, to control theadmission of the pressure iiuid to the vends of the piston valve, anauxiliary valve 8 is provided.

This auxiliary valve 8 constitutes a rod extendingv through the valvechest and through the main valve 'I therein and sealing in guidechannels in the stationary plunger assembly at opposite ends of thevalve chest 6. The auxiliary valve 8 is adaptedl to be reciprocated bythe traveling barrel of the motor through the medium of a motionreversing mechanism. Thus the lower end of the auxiliary valve 8 issecured to a rack 3U meshing with a pinion 3| rotatably supported withinthe stationary plunger assembly' 4, which pinion also meshes with a rack32 connected to -an actuating rod I0 provided with a cross head 33 onits lower end which is engaged either by a cross head 34 or a shoulder35 on the traveling barrel assembly.

The remaining structural details of the mechanism disclosed in theschematic diagram of Fig. 1 will be described in connection with thedescription of operation which follows.

Assume that all the elements of the mechanism are in the position shownin Fig. 1, that the lower portion at least of the outer tubing 2 issubmerged in well oil in the casing I, that the outer tubing 2 isconnected at the surface to a discharge line for pumped oil, and that asubstantially continuous stream of clean oil (hereinafter referred to aspressure oil) is forced down from the surface through the'inner tubing3.

The pressure fluid from tubing 3 passes through longitudinal'passages 36into the pocket 28 of the valve from which it is admitted throughpassages 3'! to the under side of the shoulder 20 on the travelingbarrel, which shoulder constitutes the moving piston in the workingchamber. 'It will be observed that at the same time the upper end of theworking chamber above the shoulder which, with the valve 1 in lowermostposition, is connected through exhaust passages to the space surroundingthe stationary motor plunger and within the projecting upper end of thetraveling barrel I9. This space within the upper end of the travelingbarrel is vented to the outer tubing through ports 40 at the upper endof the barrel.

The traveling barrel thereupon moves upwardly, carrying with it the pumpplunger 22. Movement of the pump plunger rod 2I upwardly through theblock I2 displaces a quantity of oil in the outer tubing 2 in which thepump mechanism is submerged, forcing this oil upwardly to the surfacethrough the tubing 2. At the same time the upward movement of thetraveling motor barrel and pump plunger assembly 5 causes the cross head34 to engage the cross head 33 on the auxiliary valve actuating rod I8,moving the latter upwardly and causing the rack 32 to rotate the pinion3| in a counterclockwise direction, thereby forcing the rack 33 and theauxiliary valve 8 downwardly. The traveling motor barrel and pumpplunger assembly 5 continue their upward movement and the auxiliaryvalve 8 continues its downward movement until the parts are in therelative position shown in Fig. 2. (It will be'observed that in Figs. 2,3 and 4, the well casing I has been omitted to simplify the drawings).

With the parts in the position shown in Fig. 2, the central valve pocket28, which is at all times supplied with pressure fluid from the innertubing string 3 through the passages 36, is connected through passages4I in the piston valve 1 with a passage 42 in the auxiliary valve 8, theopposite end of which passage communicates with the extreme lower end ofthe valve chest 8,'thereby applying pressure fluid to the under end ofthe piston valve 1. In the position of the parts shown in Fig. 2, theupper end ofthe valve chest G is connected by passages 43 in theauxiliary valve 8 and passages 44 in the piston valve with the upperpocket 21 of the piston valve, which pocket is also connected to theexhaust passage` 39 leading to the exterior of the plunger rod. As aresult of the differential pressure betweenA the pressure fluid suppliedthrough the inner tubing 3 and the pumped fluid and exhaust fluidin theouter tubing 2 applied to the piston valve 1, the latter moves upwardlyinto theiposition shown in Fig. 3.

With the parts'in the position shown in Fig. 3 pressure fluid from thevalve pocket 28 is applied through passages 38 to the upper end of theworking chamber above the shoulder 28, which constitutes the movingpiston within the working chamber, and the lower end of the workingchamber is connected through passages l1 to the lower valve pocket 25,which is connected through exhaust passages 46 to the space surroundingthe plunger below the shoulder I1, from which space exhaust fluid isexhausted through ports 41 to the outer tubing 2 and thence up to thesurface.

rI'he differential pressure acting upon the shoulder 28 thereupon forcesthe latter, together with the traveling motor barrel and pump plungerassembly 5, down into the position shown in Fig. 4.

During the preceding upward movement of the pump plunger 22 oil wasdrawn into the pump barrel I4 through the standing valve 25. Therefore,during the downward movement of the pump plunger 22 the uid previouslydrawn into the pump barrel is displaced upwardly past the' check valve28 in the pump plunger through the hollow pump plunger and the ports 24into the outer tubing 2. The area of the pump plunger rod 2l ispreferably equal to half'the area of the plunger 22 so that equalquantities of pump iluid are discharged into the outer tubing 2 on boththe up and `down strokes of the plunger.

Of course, as `the traveling motor barrel and pump plunger assembly 5travel down into the position shown in Fig. 4, the auxiliary valve 8 wasmoved into its uppermost position. In this position pressure fluid isadmitted from the pocket 28 in the valve 1 through passages 48 in themain valve and passage 49 in the auxiliary valve to the upper end of thevalve chest, thereby applying pressure iluid to the upper end of thepiston valve. At the same time the lower end of the valve chest isconnected through passages 50 in the auxiliary valve and passages 8l inthe main valve with the valve pocket 28, which is connected throughpassages 48 with the outer tubing. The piston valve 1 thereupon movesdownwardly into the lowermost position in which all of the parts arepositioned as shown in Fig. i, thereby completing a cycle of operation.

It is essential to the proper operation of a pump mechanism of the typedescribed that the piston valve 1 substantially complete its movementbefore thetraveling barrel of the motor begins to move and it is alsoimportant that the valve thereafter remain in the end position to whichit was last moved until the traveling barrel has completed its movement.

Completion of the movement of the piston valve before any appreciablemovement of the traveling barrel is effected in the mechanism disclosedby virtue of the-fact that the pressure of the operating duid requiredto shift the piston valve is less than that required to shift thetraveling barrel. 'I'hus the upper and lower faces of the piston valveare of equal areas so that the differential pressure required to shiftthe piston valve is only that necessary to overcome the friction betweenthe sliding parts. On the other hand, a greater differential pressurebetween the operating fluid supplied through the inner tubing 3 and theexhau-t fluid and pump fluid discharged through the tubing 2 is requiredto shift the traveling barrel because movement of the latter is not onlyopposed by the pressure of the exhaust fluid acting against the end ofshoulder 20 (the area of both ends of which are the same) but also bythe pressure of theY exhaust fluid acting against the pump plunger. Inother words, the exhaust fluid is always exerting its pressure againstan area on the traveling motor barrel and pump plunger assembly that islarger than the area to which pressure fluid is applied, whereas thesurfaces of the piston valve exposed to pressure fluid and exhaustfluid, re Vpectively, are'always equal.

After having been once moved to an end position, the piston valve isurged to remain in that position not only because of the pressure fluidtrapped in the opposite end of the valve chest but also by virtue of thefact that the auxiliary valve 8 is moved, during the major portion ofthe movement of the traveling barrel, in a direction tending to maintainthe piston valve in the end position to which it was last shifted. Thus,in Fig, l the piston valve 1 is in lowermost position and during theupward movement of the traveling barrel into the position shown in Pig.2 the auxiliary valve 8 is moved downwardly, thereby tending to maintainthe piston valve in its lowermost position. Similarly, during thesequence of operations occurring between the positions indicated inFigs. 3 and 4, the piston valve is urged upwardly, thereby tending' tomaintain it in its upper position, by the upward movement of theauxiliary valve. i

'I'he schematic diagrams of Figs. 1 to 4 are provided principally toillustrate the principles of operation and make it easier to understandthe construction and operation o fnthe practical pump illustrated inFigs. 5 to; 18v in which, because oi' the fact that diametrical space isat a premium, a pumping capacity suicient to make the unit practicableis obtained by making the stroke of the traveling motor barrel and pumpplunger assembly, and the over all length of the unit, much greater inproportion to the diameter of the unit than is shown in the schematicdiagrams of Figs. 1 to 4. It is also to be noted at this point that thepracticable pump to be described incorporates many structural featureswhich in the interests of clarity are omitted from the schematicdiagrams although many of these features in themselves involveinvention.

However, the schematic diagrams of Figs. 1 to 4 illustrate some of theadvantages of that feature of my construction consisting in theVmounting of the motor valve mechanism vwithin of Fig. 1 that myconstruction provides relatively short straight passages between thevalve chest and the-two ends of the working chamber and between the'valve chest and the exhaust passages surrounding the plunger memberabove and below the working chamber. My construction also reduces thelength of the pressure iluid conduits (passages 36) connecting the innertubing with the valve chest and reduces the pressure drop in thosepassages. It should be noted particularly that in my construction only asingle passage for conveying iluid (the fluid discharged from the pumpintermingled with motor exhaust fluid from the passages 46) upwardlypast the motor, is necessary; therefore, the entire annular spacebetween the motor barrel I9 and the outer tubing 2 can be used for thispurpose.

Construction of practicable pump as illustrated in Figs. 5 to 18 Theouter tubing assembly That portion of the outer tubing 2 immediatelyabove the pump is joined by a nipple 52 (Fig. 5) to a coupling 53. Asshown in the drawings, the nipple 52 is expanded at its lower end andinteriorly threaded to screw onto an exteriorly threaded portion of thecoupling 53. The exterior diameter of the lower -portion of the nipple52 and of coupling 53 is slightly greater than the body of the tubing 2(not shown' in Fig. 5) and the upper end of nipple 52, but is of sub-`to accommodate the outer tubing itself. The

coupling 53 projects inwardly beyond the inner surface of the lowerenlarged portion of the nipple 52 and constitutes a guide for the member10 to be described later. The upper edge 53a of the coupling 53constitutes a shoulder for supporting a skirt 13 to be described later.

Threaded onto the lower end of coupling 53 is a sleeve 54 which extendsdownwardly (Figs. 5, 6, 7, 8, 9 and 10) to a point immediately above thepump portion of the unit where it is threaded onto a pump supportingcoupling 55. Attached to the lower end of the pump supporting coupling55 and extending downwardly therebelow is another sleeve 56 (Figs. 10,11 and l2) extending substantially to the lower end of the unit, whereit is threaded onto a gas anchor coupling 5l. The anchor coupling 51 isadapted t'o have screwed thereinto an upper end of any standard gasanchor for separating gas from the oil before it enters the pump barrel.

The stationary motor plunger and pump barrel assembly Referring first toFig. 10, the stationary motor plunger and pump barrel assembly, which isdirectly supported from the pump supporting coupling 55, comprises ahollow stem 58 having a beveled face 59 which rests against and sealswith a complementary face on the upper end of coupling 55. The hollowstem 58 together with the coupling 55 constitute the elements defining apartition in the outer tubing to permit the portion of the outer tubingthereabove to be used as a discharge passage for oil to the surfacewhile the portion of the outer tubing therebelow contains well-oil atrelatively low pressure.

Threaded onto the upper end of the hollow stem 58 is a supporting column60, which is of tubular construction but privided with diametricallyopposite longitudinal slots Gila serving as guides for the cross head towhich the traveling barrel is attached. The supporting column i@ extendsupwardly (Figs. 10 and 9) and is connected at its upper end by screwthreads to the lower end of a, nipple 6|, which constitutes the housingfor the auxiliary valve motion reversing -mechanism. The nipple Si isattached at its upper end by screw threads to a block 52 constitutingthe lower end closure wall of the valve chest 6. Block 62 is connectedat its upper end to the lower end of .a sleeve 63 defining the lowerportion of the valve chest and also the lower shoulder of the motorplunger that seals with the traveling barrel and closes the lower end ofthe working chamber. To this end packing rings 64 are provided on theexterior of sleeve 63 to eifectively seal with the traveling barrel. Thepassages 46 for communicating the valve chest with the exterior of theplunger rod below the working chamber and the passages 3l forcommunicating the valve chest with the lower end of the working chamberare formed in the sleeve 63.

At its upper end the sleeve G3 is joined by screw threads to a sleeve65, which constitutes that portion of the plunger rod of the motor whichdefines the inner wall of the annular working chamber and also the midportion of the valve chest.

Sleeve 65 is attached by screw threads atits upper end to the lower endof a sleeve 5B which dennes the upper portion of the valve chest andalso the upper shoulder of the motor plunger that seals with thetraveling barrel and closes the upper end of the working chamber. Sleeve66 is provided with packing rings 61 (Figs. 7 and 6) for sealing withthe traveling-barrel andcon- `tains the passages 38 for communicatingthe valve chest with the upper end of the `working chamber. and exhaustpassages 39 for communicating the upper pocket 21 of the valve with theouter tubing.

Sleeve 66 is connected at its upper end by screw 'threads to a block 68constituting the upper end closure wall of the valve chest. Sleeve 66and block 68 contain the longitudial passages 36 for connecting theValve chest to the upper end of the stationary plunger rodrwhichisexposed tothe pressure fluid delivered through the inner tubing. Thesepassagesterminate, at the upper end of sleeve B andthe lower end ofblock |50,` in annular passageways 35a to provide free fluid connectionbetween those portions of the passages 36 in the twoblocks regardlessoi' whether or not they are aligned with each other. i

The block 68 constitutes a guide for the upper end of the auxiliaryvalve 8 and is therefore provided with ventports 68a for connecting theupper end of the auxiliary valve guide channel "to the space within theouter tubing sleeve 54 which is filled with exhaust and pumped fluid.

The upper end of block 68 is threaded into the lower endof a sleeve 69,which in turn is threaded at its upper end into the lower end of acoupling 'I0 which has attached thereto at its upper end a deflectingcone ll for spreading the skirt 'I3 in a manner to be described later.

As shown in the schematic diagrams of Figs. l to 4, the inner tubing 3is solidly attached to and supported from the stationary plungerassembly 4 of the pump. Such construction would be undesirable inpractice as the relatively enormous weight of the inner tubing mightproduce severe stresses in the pump plunger which would distort it andprevent satisfactory operation. For this reason ythe expansible skirt 13(Fig. 5)` is provided for directly supporting the weight of the innertubing from the coupling 53 in the outer tubing and a sliding butfluid-tight connection is provided between the coupling 10 `on the lowerend of the inner tubing 3 and the upper end of the stationary plungerassembly, which upper end is constituted by the coupling 12 anddeflecting cone 1l in Fig. 5. The coupling member 12 on the lower end ofthe inner tubing 3 is therefore provided with an inner downwardlyextending sleeve 14 which passes downwardly through the deflecting cone'H and is sealed therewith by packing members lla. The sleeve 14 isprovided with a shoulder 14h thereon for limiting upward movement of thesleeve 14 with respect to the cone 1| constituting the upper end-ofthestationary motor plunger assembly. However, downward movement of thesleeve 14 is limited only by engagement of the skirt/13 on the coupling12 with the shoulder 53a on coupling 53 in the outer tubing so that `theentire weight of the inner tubing 3 is borne by the coupling 53 whereasthe entire weight of the stationary motor plunger and pumpbarrelassembly is borne by the outer tubing through the lower coupling 44(Fig. 10).

The lower end of the sleeve 14 is provided with perforations 14otherein, permitting high pressure fluid to pass from sleeve 'i4 into thesurrounding space within the coupling 10 and the sleeve 69, from whichpoint it is free to` pass down into the hollow upper end of block 68 andthence through the passages 36 to the valve chest.

The lower endof sleeve 14 is closed by a bush- 'ing l5, which'snuglyengages a vplug rod 10 having an enlarged head 16a on the lower endthere- 'of which seals a vent 68h provided in the upper end of block 60.The rod 16 is provided on its upper and with a nutlllib so that when thesleeve 14 is elevated by lifting the inner tubing string 3; in theprocess of removing the pump from the well, the bushing 15 engages thenut lib on the plug rod 16 and lifts the head 16a clear of the aperture60h, thereby permitting fluid standing 'in the inner tubing 3 -to drainout through the ports 60a into the outer tubing.`

` Auxiliary valve The auxiliary valve 8, which is shown constructed inone piece in the schematic diagrams of Figs. 1 to 4, is in thepracticable pump illustrated in Figs. 5 to 18 made in several parts.Thus the upper end of the auxiliary valve is shown in Figs. 6 and '7 ascomprising a rod 00 having the grooves 43 and the centrall passage 49therein. This rod 80 is joined at its lower end by screw threads to arod 8| (Figs. 7 and'8) constituting the'central portion of the auxiliaryvalve and winch in turn is joined by screw threads at its lower end tothe upper end of a rod 82 having the passage 42 and the grooves 50therein.

The lower end of the rod 82 projects through the block $2 dening the`lower end of the valve chest (Fig. 9) and is provided with an annulargroove 82a in its projecting lower end. which interlocks with a shoulder83 on the upper end of the rack 30, which engages with the pinion 3|.The pinion 3l, as previously mentioned, is rotatably supported in thenipple 6I and also meshes with the rack 32. `The latter is provided witha shoulder 84 on its lower end whichengages with an annular groove'll`in the upper end of the auxiliary valve actuating rod l0. `The racks 30and 32 are supported for free longitudinal movement within the nipple 6lby providing grooves in the nipple for receiving the racks, as shownclearly in the cross section of Fig. 15.

The stroke of the auxiliary valve and of the auxiliary valve actuatingrod I0 is much less than the strokeof the traveling barrel, theauxiliary valve being shifted during only the last portion of eachstroke of the traveling barrel. In order to maintain the auxiliary valvein each end stroke position until it is positively displaced therefromby the next movement of the traveling barrel in the opposite direction,the rod i0 is provided with grooves |0a containing expansible rings I0bwhich expand into recesses l0c and l0d in the upper end of thesupporting column 60 when the rod I 0 is in its lowermost and itsuppermost positions, respectively. The force of `the rings I0b issufllcient to retain the rod I0 in the end stroke position into which itwas last moved but is not sufilcient to prevent the rodbeing moved whenpositively shifted by the traveling barrel. e

l The cross head 33 on the lower end of the actuating rod l0 isconstituted by a metal block extending crosswise through an apertureprovided therefor in the lower end of rod l0, the ends of this block 33fitting in guideways provided therefor in the traveling barrel to bedescribed later. Thus 'the adjacent portion |00 of the traveling barrelis provided with groovesfor receiving the ends of the cross head 33, thelength ofthe grooves being equal to the difference between the stroke ofthe traveling barrel and the stroke ofthe auxillary valve so that theauxiliary valve will `be shifted into anew end position only during thelatter portion of each stroke of the traveling barrel. InA the drawingslboth the` traveling barrel and the auxiliary valve are shown inlowermost position in which the ends of the cross head 33 have beenengaged by the shoulders at the upper ends of the guide channels orgrooves |00. 1 On Construction of: the piston valve The piston valve 1is constructed in three parts. Thus it comprises an upper member 86which seals about the rod and is yprovided with an upper shoulder 81(Fig. 6) and a' lower shoulder 88 (Fig. 7) which seal with the .wall ofthe valve chest and define therebetween the upper valve pocket 21. Themember 81 is joined at its lower end to the upper end of a sleeve member89 which contacts neither with the ad,- jacent portion 6| of theauxiliary valve nor the walls of the valve chest, and is provided withperforations 89a to permit free passage of iluid therethrough.l Thesleeve member 89 isprovided with a shoulder 89b immediately below theperforations 89a and `detent rings 89e are preferably provided on theshoulder 89h to provide a yieldable mechanical locking mechanism tendingto retain the piston valve in its'uppermost position after having oncebeen moved into that position. As vshown in Fig. 7, .the piston y'valveis in its lowermost position, in which the detent rings 89e aresubstantially completely pressed within the shoulder 89h. However, whenthe valve is moved into its uppermost position the detent rings 89e riseslightly above a shoulder 65a in the sleeve 65 constituting the adjacentportion of the valve chest wall. The detent rings thereupon expand and,when the valve tends to return, the rings bear against the shouder 65aand tend to resist such return. However, when pressure iluid is appliedto the end of the piston valve the force applied to the valve isrelatively great as comparedv to the resistance to motion produced bythe detent rings 89o and the latter compress and permit the valve tomove downwardly. For a substantial distance below the shoulder 89h themember 89 is imperforate and cylindrical in shape and of such dimensionsthat it contacts neither the auxiliary valve nor the walls of the valvechest. At the lower end of this portion there is provided anothershoulder 90 (Fig. 8) having detent rings 90a thereon for engaging belowa shoulder 650 in the sleeve 65 whenl the valve is in lowermostposition. These detent rings 90a function to yieldably retain the valvein lowermost position in exactly the same manner as the detent rings 89etend to maintain it in its upper position. A small section of member '89below the shoulder 90 is provided with perforations 9| to permit freepassage of iluid therethrough. The lower end of the sleeve member 89 isattached by screw threads to a member 92 corresponding to the uppervalvemember 86 having upper and lower shoulders 93 and 94,respectively.. which seal with the walls of the valve chest and dene thevalve pocket 29. l

tween the two resides in the fact that the valve has been greatlyelongated in the practical modiiication by, in effect, breaking it atthe middle and interconnecting the two parts with the sleeve member 89.f l

The traveling motor barrel As has been previously explained, thetraveling barrel of the motor is rigidly connected to and reciprocatesthe pump plunger. Referring iirst to Fig. 10, the upper end of the pumpplunger rod 95 is screwed onto a downwardly depending stub shaft 96 on acylindrical member 91 which is solidly attached to a cross head 98,which extends through an orifice provided therefor in the member 91. Theouter ends of cross head 98 extend through and are ilush with the outersurface Vof a collar 99, which is screwed into the lower end of atubular member |00, constituting the lower section of the travelingbarrel. At its upper end the tubular member |00 (Fig. 8) is threadedontoa coupling |0|, which coupling is ground to seal with the adjacentportion 85 oi the stationary plunger rod. The coupling member |0|therefore constitutes the piston element of the motor which divides theworking chamber into two parts. It will be observed that the tubularmember |00 seals with the packing rings 64 on the sleeve 63 which denesthe lower end of the working chamber of the motor.

'I'he coupling member |0| is joined at its upper end by screw threads toa tubular member |02 constituting the upper portion of the travelingbarrel,r this portion sealing with packing rings 61 on the sleeve 66dening the upper end of the working chamber, and extending upwardlytherebeyond a substantial distance, as shown in Fig. 6. This uppersection of member |02 is provided with apertures |02a to provide freeflow of iluid from the exhaust passages 39 and the passages 68a. Acollar |03 is provided on the upper end of the tubular member |02 whichslides along the sleeve 69 and acts as a guide for the upper end of thetraveling barrel.

Pump unit Referring to Figs. 10 and 11, the upper end of the pump barrelcomprises a tubular member 05 threaded into they lower end of the hollowstem 58, which seats within the pump supporting coupling 55. Packingrings |05a are preferably provided to form a seal between the barrelmemb'er |05 and the upper end of the pump plunger rod 95.

The barrel proper of the pump is constituted by a sleeve 06 screwed ontothe lower end of the tubular member |05. The sleeve, |06 is providedwith ports |06a therethrough to permit fluid from the well to surge inand out of the upper end of the barrel as the plunger reciprocates. Thelower end of the sleeve |06, constituting the pump barrel, terminates(Fig. 12) in a coupling |01' which serves to secure in position in thelower end of the sleeve |06 a standing valve seat |08 and valve cage|09, within which the ball valve 23 is positioned. 'I'he lower end ofthe coupling |01 is threaded to receive an oil .inlet pipe (not shown)extending downwardly into the well.

The pump plunger assembly comprises the hollow plunger rod 95 (Fig. 10)previously menplunger proper which seals with the pump bar-1 rel |25.`Thus the cylindrical member ||4 is supported between a shoulder I I3aon member'l I3 and the lower endrof the coupling *membery I I2. Thecylindrical member i I5 is similarly support ed between a shoulder I|3bon member ||3 and a coupling member IIB screwed onto the lower end ofmember I I3. The coupling members ||I and |I2` lserve to supporttherebetween a valve seat cooperating'with a ball valve YI I8, and 'a'.member III positioned belowl the coupling member l" and a bushing '(thelather constituting the extreme lower end of the pump plunger) serve toretain a second valve seat I2| which co-f operates with a ball valve|22; The two valves, including balls III and I22, together function thesame as the single valve ball. 23 vshown'jin the schematic drawings ofFigs. l to 4to permit entry of fluid compressed below the pump plungerup through u the hollowv plunger rod,` vbut prevent its return. Thefluid flowing upthrough the hollow plungerorod escapes to the outertubing through ports 24 (Fig. 10) `in the upper end of the hollow pumpplunger rod.

Traveling barrel Iockinmmechanisrn Pumps of the generaltype to whichthis invention relates vdependfor their properoperation on definitesequential movements of the different parts. Should the different parts,such as the traveling barrel assembly, the piston .valve and theauxiliary valve, be accidentally initially placed'in certain relativepositions, they might fail tooperate in response tothe application ofpressure fluid thereto. I therefore provide a special locking mechanismfor maintaining the traveling barrel assembly in lowermost positionwhile the device is in transit and is being lowered into the well withmeans for automatically unlocking the traveling barrel assemblyafter infstallation in the well. Referring to Fig. 10, the locking mechanismtherein disclosed comprises a detent ball |23- positioned in apassageway- |24 in the block 55, the length of the passagewayulu lbeingslightly less than the `diameterof the detent ball |23 and the outeredge ofthe passageway being normally closed by a plunger |25 fitted in avertical cylindrical passage |25 in theblock 58. `The upper end ofpassage |25 opens .into the outer tubing above the sealing surface 59 onblock 58 and the lower end of the passage opens toI the exterior belowthe sealing surface'58-` The plunger -|25 is normally retained inuppermost position by a helical spring |21` positionedthere'belovlh inwhich position the detent ball I23'is forced inwardly beyond the innersurface of the block 58' and into engagement with a portion |28 of thepump plunger 55, which'is of reduced diameter. ,It will be apparent thatso long as'plunger |25 is`in the uppermost position shownin Fig.`l0, anyupward movement of the pump plunger 95 and the travel-` ing barrelassembly connected thereto willbe prevented by engagement of the detentball |23` force of the helical 'spring f|2`| and move the plungerdownwardly until a' recess |23 therein is juxtaposed' to the detent'ball|23; permitting the latter to move outwardlyaway from thepump plungerrod 55. f y

The differential pressure necessary to move the plunger |25 is `producedwhen the pump, after being seated in the well with thebeveled face `53resting againstand sealingrwith the cooperating face on the pumpsupporting coupling 55, is conditioned for service by filling the outertubing 2 with oil. As soon as any appreciable head of oil has been builtup within the outer tubing,the pressure ofthe oil on the upper end ofplunger |25 is sutilcient to depress'the latter to release the detentball |23 and permit the reciprocation of the traveling motor barrel andpump'plunger assembly. o

A modified formof lock is shown in Fig. 10A, which shows a section of acompleted pump correspondingin general to that disclosed in Fig. l0 andcorresponding parts offwhich bear correspending reference numerals withthe prime mark sulxed. The essential difference betweenv the lockingmechanism disclosed in Fig. 10A over that disclosed in Fig. 10 is thatwhereas the ball detent is released in Fig. 10 by the application offluid pressure, the detents `in Fig. 10A are automatical- `ly releasedin response to the seating of the pump.

Thus the'detent balls |23' positioned in es |24.' in the block 58" are,before the pump is installed, forced in'to engagement with the reducedportion |2' of thepump plunger'rod 55' by a skirt member |29 which isforced downwardly by a helical spring |30 positioned thereabove tovbring the upper reduced portion ISI of the skirt juxtaposed to the outerends of the passages |24'. The skirt member |29 in this modificationconstitutes the member which seats against the pump supporting coupling55` and is provided'with a beveled face 59' for this purpose. The skirtmember is also slidable vertically alongthe hollow stem 55 but has itsvertical movement limited by a shoulder |32 through which, when the pumphas been seated, the entire weight and all downward force exerted on thepump are-transmitted to the skirt Amember |29 and thence V.to the pumpsupporting coupling 55'. It willbe observed that as soon as the pump hasbeen`j seated; as shown inv Construction of joints between` sections Asdescribed, my practical `pump is made up of many `different ytubular or.cylindrical parte joined together by screw threads. In many instances.adjacent parts u V that mustbe concentricwith respect to each other.Thus, for, example, consider the joint between the tubular block 52V(Fig. 8) and the sleeve 63 thereabove, in ,which the bore of the blockmust be very accurately aligned with the bore of the sleeve if theauxiliaryvalve and main valve are to move freely and also seal witheachother and with the bores of the block 52 andsleeve; respectively.Heretoforeyin order to closely iit such parts, it has .o been`considered. necessary eitherto cut the threads exactly concentric withthe bores, or to drill or ream the bores` oi' the parts after they havebeen screwed together.

have. bearing surfaces Both methods are expensive andI avoid them byusing square threads4 to join the parts instead of the conventionalV-threads, and aligning the parts with a mandrel while they are beings'crewed together. This method, as applied to the joint between block 62and sleeve 63 is illustrated in Fig. v19, in which the square threads onthe sleeve 63 areA indicatedat 63a, the square threads on the` blockl 62are indicated at 62a; and the aligning mandrel indicated in dotted linesat |40. 'Ihe square threads 62a and 63a. are so deep that they permitsubstantial lateral movement between the two parts and donot determinetheir alignment, merely serving to clamp the parts firmly together whilethey are maintainedin alignment by the mandrel |40. After the joint ismade and the mandrel |40 is removed, the parts remain in alignmentbecause of the friction between the threads and between the abuttingshoulders of the parts, andbecause the square threads exert no lateralforce tending to produce a lateral shift. It is to be noted that thismethod of joining. parts with their cylindrical bearingsurfaces inalignment cannot be used with V-threads because the latter areinherently self-centering, whereas square threads are not.

The method, although illustrated in detail only with reference to the`joint between block 62 and sleeve 53, is applicable to all the screwjoints in the pump between parts having cylindrical surfaces that mustbe accurately aligned, the shape and dimensions of the mandrel employedwith each joint depending, of. course, on the shapes and dimensions ofthe surfaces to be aligned. Thus where the surfaces to be aligned areouter surfaces instead of inner surfaces, the mandrel must surround theparts and in some such instances the mandrel may be split to facilitateits removal.

Installation and removal of the pump At the time of the originalinstallation of a pump as described, the outer tubing 2 before beinglowered into the well has attached thereto on its lower end the nipple52, coupling 53, sleeve 54, pump supporting coupling 55, sleeve 56, andthe anchor coupling 51,"as disclosed in Figs. 5 to 12, inclusive."Thereafter the pump unit is attached to the lower ond of the innertubing string 3 and is later lowered down through the outer tubing 2.

While supported from the lower end of the inner tubing string 3, allportions of the pump unit are sufciently small to pass freely throughthe outer tubing'. Thus at this time the sleeve 14 attached to thecoupling 12 (Fig. 5) instead of being in the position shown in thedrawings, would be withdrawn until the shoulders 'Mb rested against thelower end of the packing members 1|a, the weight of the entire unitbeing supported by the shoulder 14h. In this position the expansiblesplit skirt 13 on the coupling 12 is in its normal position in which itis substantially cylindrical in shape and of the same outside diameteras the main portion of the coupling 12.

As the assembly supported on the inner tubing string 3 approaches thelower end of the outer tubing 2, the tubular member |05 defining thepump barrel enters the pump supporting coupling 55 and passes downwardlytherethrough until the beveled face 59 seats against the upper end ofcoupling 55 (Fig. 10). Thereafter continued downward movement of theinner tubing string causes the sleeve 14 to telescope within thedeflecting cone 1|, thereby expanding the split skirt 13 until the loweredgev of the latter rests againstthe shoulder 53a on the coupling 53(Fig. 5). Thereupon the weight of the inner tubing is supported throughthe skirt 13 by the coupling 53.

The pump parts are so dimensioned that shortly after the beveled face 59of the hollow stem 58 (Fig. 10) seats against the pump supDOrtingcoupling 55, the enlarged head 16a (Fig. 6) seats in'the port 68h whichcommunicates the ports 68a with the outer tubing.

The pump is then set in operation by lling the outer tubing with oil tocreate sufficient pressure to actuate the plunger |25 (Fig. 10) andrelease the detentball |23 to permit reciprocation of the travelingmotor barrel and pump plunger assembly. Thereafter the inner tubingstring 3 is 4filled with pressure Afluid and a continuous stream ofpressure fluid is forced therethrough to operate the pump in the mannerdescribed with reference to the schematic drawings of Figs. 1 to 4. Itwill be observed that when the inner tubing string is filled with liquidunder pressure the enlarged plunger head 16a (Fig. 6) is maintainedtightly seated by the pressure of the fluid thereabove.

The installation and operationof a pump having a locking mechanism asdisclosed in Fig. 10A is identical with that described except that it isunnecessary to ll the outer tubing with oil preliminary to starting thepump since the 4detent balls |23 are automatically released when thepump is seated.

If for any reason it becomes necessary to remove the pump from the wellafter it has been in operation, such removal is accomplished by simplydisconnecting the supply of pressure fluid from the inner tubing string3 at the surface of the well and pulling the inner string. Initialupward movement of the inner tubing string 3 elevates the coupling 12(Fig. 5), lifting the split skirt 13 away from the deflectng cone 1| andthe shoulder 53a, permitting the latter to contract to the diameter ofthe upper or main portion of the coupling 12. Thereafter continuedupward movement first causes the bushing 15 (Fig. 2) in the lower end ofthe sleeve 14 to engage the nut 1Gb on the upper end of the plug rod 16and lift the enlarged head 16a clear of the opening 68h which itlnormally closes. This permits the oil standing in the inner tubingstring to drain out through the opening 68h and the ports 68a into theouter tubing as the inner tubing and the pump are withdrawn, therebypermitting what is termed a dry job of pulling. Of course, furtherupward movement Aof the inner tubing string causes the shoulder 14h cnthe sleeve 14 to engage with the under edge of the packing member Hafollowing which further upward movement of the inner tubing stringcarries the pump up throughthe outer tubing string 2 to the surface.

After theA pump has been removed from the well, it will be observed fromFig. 10 that the motor end of the pump may be completely detached fromthe pump end by breaking the threaded vconnection between the hollowstem 58 and the supporting column 60 and the threaded connection betweenthe upper end of the pump plunger rod and the stud shaft 96 on thecylindricalmember 91. This feature, whereby the pump unit -may bereadily removed from the motor unit, is very important for the reas'onfact that the pump must with clean filtered oil from enclosed piston orplunger even though the that a pump unit is apt to wear much morerapidly than the motor unit by reason of the handle oil from the wellcontaining sand and other abrasive material whereas the motor unit canbe supplied the surface.

The ready separation of the pump and motor units is also desirable inthat it permits `ready substitution of pump units of differentcapacities, thereby permitting the use of the same motor in wells ofdifferent depths without increasing the pressure of the operating fluidsupplied to the motor in the deeper well by merely employing a pumpingunit of smaller capacity in the deep well than inthe shallow well.

It should also be noted that, by virtue of the fact that the motor endof the pump is fully enclosed and constantly fioodediwith filtered oilfrom the inner tubing 3, no bearing surface of the mechanism 'in themotor unit comes in contact with the pumped fluid.

Of course, as previously mentioned, probably the greatest singleadvantage of my construction is that the use` of the traveling motorbarrel and stationary plunger assembly with the valve mechanismpositioned within the plunger rod eliminates many restricted passagesand irregular passages having right angle turns therein, therebydecreasing fluid friction and adding to the mechanical emciency of theunit. I'Ihis advantage can best be emphasized by comparison. Thus I amable to obtain an equal or greater pumping capacity with an assembly ofthe type described having an over all diameter of only 2 and sths inchesthan was formerly obtained with a pump having an over all diameter of 4inches.

`A substantial advantage results in my construction from the fact thatboth the traveling motor barrel and stationary motor plunger aresupported from their lower ends and the inner tubing string is supportedindependently of the stationary plunger assembly, thereby eliminatingunnecessary compression or tension strains in the plunger and barrelassemblies which might i cause them to warp and freeze when installed inthe well. The free-end barrel is less rigid and will flex enough toalign itself with the bore of the barrel may be off center a fewthousandths of an inch or may not be absolutely straight.v

` The use of the automatic lock for the traveling barrel is a verydesirable feature in that it makes the pump substantially fool-proofeven when installed and operated by unskilled labor. The use of theexpansible skirt for supporting the weight of the inner tubing from theouter l tubing independently of the pump mechanism also tends to makethe device more fool-proof as it prevents any possible damage to themechanism resulting from too rapid landing of the pump in the'bottom ofthe tubing by a careless well crew.

Although, as previously stated, the motor unit is preferablysuppliedwith clean filtered oil through the inner tubing string '3, thetubing itself often contains a certain amount of dirt, scale, sediment,etc., which it is desirable to keep out of the motor parts. Suchdeposits are prevented in large measure from reaching the working partsof the motor by the sleeve 'Il (Figs.

5 and 6) having the perforations Nc therein, These perforations filterthe oil to a. certain extent and ,the tube also acts as a sort of a.trap, heavy foreign particles in the oil therein tending to settle tothe bottom of the sleeve Il about the plunger rod 18 instead of passingout through the perforations Tlc.

Although the invention has/been described with reference to a particularembodiment thereof to simplify the conveying of a full understanding `ofthe essential principles involved, it is to be understood that theinvention is not limited to the specific structures shown but insteadisto be limited only as set forth in the appended claims.

1. In a fluid-actuated Well pump adapted to be positioned in a well andhaving pressure uid and exhaust fluid connection with the surfacethrough separate conduits, a reciprocating pump unit having astationaryelement and a reciprocating element, a motor unit comprising astationary plunger assembly adapted to be connected to the stationaryelement of the reciprocating pump unit,

and a cooperating reciprocable cylinder assembly adapted to becoupledtothe reciprocating element of the pump unit and defining together withIsaid plunger assembly a working chamber having a reciprocable pistonelement therein, valve means for said motor unit incorporated withinsaid stationary plunger assembly for controlling the admission ofpressure iiuid to and the discharge of exhaust fluid from opposite endsof said working chamber, said plunger assembly also defining uidpassages extending directlyfrom said valve means to said working chamberand from said valve means to said pressure fluid and exhaust uidconduits, respectively, and means for actuating said valve means inresponse to'predetermined movements of said cylinder assembly.

2. In a huid-actuated well pump adapted to be positioned in a well andhaving fluid connection with the surface through an outer tubing for thedischarge of exhaust fluid and pumped fluid and separate fluidconnection with the surface through a. smaller inner tubing positionedwithin the outer tubing for the reception of operating fluid under highpressure, a motor unit comprising a stationary plunger assembly and acooperating reciprocable cylinder assembly adapted to be submerged inexhaust and pumped uid within said `outer tubing and defining betweenthem a working chamber, a reciprocable piston elementin said chamber,valve means incorporated within said stationary plunger assembly forcontrolling the admission of pressure ud to and the discharge of exhaustfluid from the opposite ends of said working chamber, said plungerassembly also defining fluid passages extending directly therethroughfrom said valve means to said working chamber and from said valve meansto the duid surrounding said unit within said outer tubing, and to saidinner tubing, respectively, means for actuating said valve means inresponse to predetermined' movements of said cylinder assembly, a pumpunit, and means for actuating said pump unit in response toreciprocation of said cylinder assembly.

3. In a fluid-actuated well pump adapted to be positioned in a with thesurface through an outer tubing for the discharge of exhaust nuid andpumped fluid, and

well and having fluid connection.

' Y having chambers therein said chamber, said unit being adapted to besubmerged in uid in said outer tubing and positioned below the lower endof said inner tubing, said plunger member having a cavity thereinconstituting a valve chest, a reciprocable valve in said valve chest,means forming a iluid connection between said inner tubing and the upperend of said plunger member, an operating uid inlet port in said valvechest and a passage in said plunger member connecting said inlet portwith said end of said plunger member, exhaust ports in said valve chestand passages extending through said plunger member for connecting saidexhaust ports with the exterior of said member in communication with thefluid in which said unit is submerged within said outer-tubing, otherports in said valve chest and passages in said plunger membercommunicating said other ports with the opposite ends of said workingchamber, said reciprocable valv'e for selectively interconnecting saidinlet and exhaust ports with said other ports to supply operating duidto either end of and to exhaust fluid from the other end of said Workingchambe:` depending upon the position of said valve, and means forshifting said valve in response to predetermined movement of saidtraveling cylinder, a pump unit, and means for actuating said pump unitin response to reciprocation of said cylinder assembly.

4. In a uuid-actuated Well pump adapted to be positioned within a welland having iiuid connection with the surface through an outer tubing forthe discharge of exhaust uid and pumped fluid 'and separate uidconnection with the surface through a smaller inner tubing positionedwithin the outer tubing for the reception of operating fluid under highpressure, a motor unit adapted to be submerged in fluid within saidouter tubing and comprising a stationary plunger assembly and acooperating reciprocable cylinder assembly, the two definingtherebetween a. working chamber, a piston element reciprocable in saidchamber, said plunger assembly comprising an elongated plunger memberhaving a cavity therein constituting a valve chest, valve meansincorporated within said valve chest comprising a reciprocable valve rodextending through said chest and projecting therebelow and a uidoperated piston valve positioned concentrically about said valve rod andhaving a sliding sealing t within said valve chest and about said valverod, an inlet port in said chest and a passage in said plunger membercommunicating said inlet port with the upper end of said plunger'member, means communicating the upper end of said plunger member withsaid inner tubing, an exhaust port in said chest and a passage throughsaid plunger member communicating said exhaust port with the surface ofthe plunger member at a point therein positioned beyond said workingchamber and exposed to the iiuid in which said unit is submerged, otherports in said valve chest and other passages in said plunger membercommunicating said other ports with the surf-ace of said plunger memberat points positioned within and adjacent opposite ends of said workingchamber, said piston valve having chambers therein for selectivelycommunicating said inlet and exhaust ports with said other ports tosupply operating fluid to either end of said working chamber and toexhaust fluid from the opposite end of said working chamber when saidvalve is in predetermined positions in said valve chest, said valve rodhaving passages therein terminating in ports registering, respectively,with said valve chambers and with opposite ends of said piston valvewhen said rod is in predetermined positions for admitting pressure fluidto ,one end and exhausting uid from the opposite end of said pistonvalve to shift the latter, and means for reciprocating said valve rod inresponse to predetermined movement of said traveling cylinder assembly,a pump unit, and means for actuating said pump unit in response toreciprocation of said cylinder assembly.

5. In a fluid-actuated well pump adapted to be positioned within a Welland having fluid connection with the surface through an outer tubing forthe discharge of exhaust fluid and pumped iiuid and separate uidconnection with the surface through a smaller inner tubing positionedWithin the outer tubing for the reception of operating fluid under highpressure, a motor unit comprising a reciprocable cylinder and acooperating stationary plunger member positioned within said cylinder,said plunger member having longitudinally spaced shoulders sealing withsaid cylinder and constituting the end walls .of the working chamber ofthe motor and said cylinder having a shoulder thereon sealing with saidplunger member and constituting the reciprocable piston within saidWorking chamber, said plunger member having a cavity thereinapproximately coextensive with said Working chamber constituting a valvechest, exhaust ports in said valve chest adjacent opposite ends thereofand exhaust passages in said plunger member extending directlytherethrough from said exhaust ports to the exterior of said plungermember at points beyond said shoulders thereon for discharging exhaustfluid from said chest, an inlet port in said Achest adjacent the centerthereof and a passage extending longitudinally through said plungermember from said inlet port to the upper end of said plunger member,means for applying pressure fluid from said inner tubing to the upperend of said plunger member, other ports in said valve chest positionedbetween and adjacent to said respective exhaust ports, passagesextending directly through said plunger member from said other ports tothe exterior of said plunger member at points between and adjacent saidshoulders thereon for communicating said valve chest with opposite endsof said Working chamber, a valve reciprocable in said valve chest andsealing with the walls of said chest and having pockets therein forcommunicating one of said passages extending vto one end of said workingchamber with either said inlet port or the adjacent exhaust port andcommunicating the passage extending to the opposite end of the workingchamber either with the exhaust port adjacent thereto or said inletport, depending upon the position of said valve in said chest, and meansfor reciprocating said valve in response to predetermined movements ofsaid reciprocable cylinder assembly, a pump unit, and means foractuating said pump unit in response to reciprocation of said cylinderassembly.

6. In a uuid-actuated well pump adapted to be positioned in a well andhaving uid connection with the surface through an outer tubing for thedischarge of exhaust fluid and pumped fluid and separate fluidconnection to the surface through a smaller inner tubing positionedwithin the outer tubing for the reception of operating fluid under highpressure, a motor unit comprising a reciprocable cylinder member and acooperating stationary plunger member positioned within the cylindermember and dening with said cylinder member an annular working Chamberhaving an annular piston element reciprocable between opposite ends,plgsaid workextending from ports in said valve Vchest through saidplunger member to opposite ends of said working chamber for supplyingpressure iluid`t0 either end of said working chamber and exhaust fluidfrom the opposite' end of said working chamber, an inlet port in saidvalve chest and a passageextending through said plunger member from saidinlet port tothe upper end thereof for communicating said portwith saidinner tubing, exhaust ports in said' valve chest-and passages extendingtherefrom through `said plunger member to the exterior thereof and intocommunication with fluid within said outer tubing, an annular pistonvalve in said valve chest -reciprocable in said chest and having pocketstherein for communicating said ports connect.-

ed to Aopposite ends of said working chamberwith said inlet and exhaustports, respectively, said pockets and ports being so positioned thatwhen said piston valve is in its lowermost position pressure iluid isapplied to said working chamber to move said reciprocable cylinderupwardly, and when said valve is vin its uppermost position uid isapplied to said working chamberto move said reciprocable cylinderassembly downwardly, an auxiliary valve rod extending vertically throughsaid valve chest and through said annular piston valve and sealingtherewith, motion reversing mechanism coupling said auxiliary valve tosaid cylinder assembly whereby-movement of said cylinder upwardlyVshifts said auxiliary valve downwardly and'downward movement of saidcylinder assembly shifts said auxiliary valve upwardly, said auxiliaryvalve having passages therein terminating in ports communicating thelower end of said piston valve with said inlet port and the upper end ofsaid piston valve with said exhaust port when the auxiliary valve is inup position, and for communicating theupper end of said valve chest withsaid inlet port andthe lower end of said valve chest with one ofsaidexhaust ports when said auxiliary valve is in down position, a pumpunit, and means for actuating said pump unit in response toreciproeation of said cylinder assembly.

7. In a fluid-actuated well pump, having iluid` connection with thesurface through an outer tubing for the discharge of exhaust fluid andpumped iiuid and separate fluid connection with the surface through asmaller inner tubing positioned within the outer tubing for the`receptionrof operating liiuidvunder high pressure, a`

motor unit adapted to be submerged'in exhaust and pumped iiuid withinsaid outer tubing and positioned below the lower end of the inner tubingand having iluid connection therewith, said unit comprising a stationaryplunger member, means for supporting the lower end of said plungermember from said outer tubing, said unit also comprising a travelingcylinder assembly .reciprocable with respect to said stationarylowered'into a well through an outer tubing string while supported on aninner tubing string, and having fluid connection with both the inner andouter tubing strings when positioned in said well a stationary motorplunger member having a1 supporting base on its Alower end, acooperating seat on said outer tubing for engaging said base andvsupporting said plunger member when the latter has been lowered intoworking position within said outer tubing, telescoping sleeve means onthe upper end of said stationary plunger member for communicating saidplunger member with said inner tubingand supporting the plunger memberfrom the inner tubing while permitting a substantial amount of relativemovement therebetween, an .expansible skirt member on the lower end oi.'said inner tubing, a skirt-expanding cone on the upper end of saidplunger member and shoulder means in said outer tubing so spaced abovesaid seat that when said plunger base reaches said seat further downwardmovement of said inner tubing forces said expansible skirt down oversaid cone and expands the skirt to engage with and rest upon saidshoulder,

whereby the weight of said inner tubing is sup- Vmotor barrel`surrounding said plunger member and cooperating therewith to-dene aworking chamber, andvalve means and fluid passages in said plungermember for supplying pressure uid to said working chamber from saidinnertubing and exhausting fluid from said working chamber to said outertubing. n

9. A device as described in claim 8 in which said telescoping sleevemeans comprises a sleeve depending from and ,in communication with saidinner. tubing, said sleeve extending down into a recess providedtherefor in the upper end of said plunger member, packing means on saidplunger member sealing with said sleeve and constituting withI saidsleeve a `fluid-tight closure for said recess, a shoulder on said sleevebelow vsaid packing means for engaging therewith and limiting upwardmovement of said sleeve with respect to said plunger member, saidsleevehaving perforations therein below said shoulder for the passage ofpressure iluid into said plunger recess and longitudinal passages insaid plunger member communicating said recess with said valve means. i

10. In a :duid-actuated well pump adapted to be lowered into a wellthrough an outer tubing string while supported on an inner tubingstring, and having fluid connection with both theinner and outer tubing.strings when positioned in said well, a stationary motor plunger memberhaving a supporting base adapted to seat on a cooperating seat on theouter tubing and be supported thereby when the pump has been loweredinto working position within said outer tubing, a sleeve depending fromand in communication with said inner tubing, said sleeve extending downinto a recess provided therefor in the upper end of said plunger member,packing means on said plunger member sealing with said sleeve, ashoulder on saidsleeve below said packing means for engaging therewithand limiting upward movement of said sleeve with respect to said plungermember` and terminatingA in an orice inl the bottom of said recess, arod having a plug on the lower end thereof for closing said orice,

said rod extending up into said sleeve, a bushing `in the lower end ofsaid sleeve for guiding said rod and sealing the lower end of saidsleeve, andV shoulder means on the upper end of said rod for engagementby said bushing when said plunger member is supported by said innertubing to lift said plug from said orice and thereby establish directfluid communication between said inner and outer tubings.

11. In a huid-actuated well pump adapted to be positioned within andsupported by an outer tubing extending to the surface and in which thepump seals olf the outer tubing, whereby oil may be inducted from thewell into the pump through the lower portion of the outer tubing andpumped oil and exhaust fluid discharged from the pump may be transmittedto the surface through that portion of the outer tubing extendingthereabove, and in which the pump includes a fluid-actuated drivingmotor supplied with pressure fluid through an inner tubing which alsofunctions as a supporting vstring to klower and withdraw the pumpthrough the outer tubing; a pump body incorporating a reciprocating pumpand motor mechanism and comprising a base member adapted to seat on andseal with'a pump supporting seat in said outer tubing, said mechanismincluding a rod reciprocable in said pump body, latch means in said basemember movable into engagement with said rod when the latter is in apredetermined position for preventing movement oi said rod from saidposition, spring actuating means for moving said latch meansl intoengagement with said rod, and means rendered operative in response-toseating of said base member in said seat in the outer tubingA forreleasing said latch means from engagement with said rod.

i2. in a fluid-actuated well pump adapted to be positioned within'andsupported by an outer tubing extendingto the surface and in which thepump seals on the outer tubing, whereby oil may be inducted from thewell into the pump through the lower portion of the outer tubing andpumped oil and exhaust uid discharged from the pump may be transmittedto the surface through that portion of the outer tubing extendingthereabcve.

and in which the pump inciudes a fluid-actuated driving motor through aninner tubing which also functions as a supporting string to lower andwithdraw ie pump through the outer tubing; a pump body incorporating areciprocating pump and motor mechanism having a base member adapted toseat on and seal with a pump supporting seat in said outer tubing, saidbase member comprising a sleeve slidably mounted on said pump body iorlimited vertical movement with respect thereto, spring means fornormally maintaining said sleeve in lowermost position on said pump bodywhile permitting upward movement thereof in response to seating of thepump, said suppiied with pressure fluid mechanism including a rodreciprocable in said pump body, a detentin said pump body movable intoand out of engagement with said rod, and means on said sleeve forforcing said detent into engagement with the rod when the sleeve is inlowermost position and releasing the detent when the sleeveis inuppermost position.

13. A device as described in claim 11, in which said latch meanscomprises a plunger. reciprocable in a passage in said base, member, oneend of which passage is ported above the seating surface of said basemember and the other end of which is ported below said seating surface,a detent movable into and out of engagement with said rod, means on saidplunger cooperating with said detent to maintain the latter inengagement with said rod when the plungerv is in one end positionandrelease the detent from engagement with the rod' when the plunger is inthe other end position, spring means for normally urging said plunger insaid one end position but yielding in response to dilerential pressureapplied to the opposite ends of said passage to permit movement ofsaidplunger into said other end position, whereby said mechanism may bemaintained locked in a predetermined position during lowering of saidpump in said well and released following seating of the pump in theouter tubing by establishing a column of liquid in said outer tubingabove said pump.

ifi. In a fluid-actuated well pump adapted to be positioned in a welland having exhaust fluid connection with the surface through an outertubing string, and pressure fluid connection with' the surface throughan inner tubing string positioned within the outer tubing, a motor unitcornprising a stationary plunger assembly having a base member thereonadapted to seat on a supporting ange provided therefor in the outertubing string, a cooperating reciprocable cylinder assembly comprising acylinder of substantial length surrounding the major portion of saidplunger assembly and defining therewith'a Working chamber adjacent thecentral portion of said cylinder, said cylinder projecting substantiallyabove and below said working chamber and defining with said plungerannular passages above and below said working chamber, valve meanswithin said stationary plunger, means connecting said stationary plungerto the lower end of said inner tubing, a passage in said plungercommunicating said inner tubing with said valve, passages in said valvecommunicating said valve with said working chamber, exhaust passagesextending iroin said valve to said annular passages defined by saidcylinder and plunger assemblies above. and below said working chamber, apump positioned below said motor unit and connected thereto and adaptedto discharge pumped fluid up through said outer tubing past said mot-orcylinder, whereby exhaust oil from said Valve discharged into said outertubing through the annular passages defined between the ends of saidcylinder above and below said working chamber displaces any pumped fluidtending to approach the cooperating slidingpcontact surfaces of saidmotor mechanism. 2

15. in a fluid-actuated pump, an inner member having a cylindrical outersurface, an outer member reciprocable with respect to said inner memberand having a cylindrical inner surface spaced from and surrounding saidouter surface on said inner member, and constituting therewith the innerand outer walls of an annular working chamber, a pair of spaced apartflanges Ving chamber by passages in said inner member for controllingthe ow of fluid to and from said working chamber, means for supplyingpressure fluid to and exhausting uid from said valve, and means foractuating said valve in response to predetermined relative movements ofsaid inner and outer members.

GRANVIILE S. KNOX.

